Charging Solenoid - Page 3

hdmoxness · 02-09-2012, 06:14 PM

Here’s what I found out re solenoids through my local auto store and the rep’s calls to HQ:

Of 17 similar-looking solenoids I dug out of the NAPA/Echlin Ignition & Electrical Systems catalog and napaonline.com, I finally boiled it down to 3 possibilities:

1. ST80 12V, 4 terminals, insulated base, flat bracket, silver contacts, continuous duty for extended engagement, low current coil 16-21 ohms, 7.5V pull in voltage, about $59.

2. ST85 12V, 4 terminals, insulated base, flat bracket, copper contacts, continuous duty, 80 amps, coil 16-21 ohms, about $62.

3. ST95 12V, 3 terminals, grounded base, flat bracket, silver contacts, continuous duty, 80a, coil 16-20 ohms, continuous duty, splash proof, about $40

The cost difference appears to be in the insulated base and extra (ground) terminal—not the silver vs. copper contacts. They claim to have all three of the above in stock.

I pulled out my dead Trombetta 936-1215-011 this afternoon and I’m off to the store in the morning. Dan’s blessing of the ST85 gives me courage, so I’m likely going to go for the ST95, being grounded, silver, and more economical. I’m going to make the rep re-confirm the silver contacts in the 95 with their tech support people and I’ll verify the physical size, the mounting hole spacing, and terminal layout before forking over my money. I’ll let you know.

lonestarace · 02-09-2012, 07:03 PM

These folks are where I buy some electrical components. They have every shape, size, make, model of relay/solenoid imaginable.

relays continuous duty 12 volt & 24 volt DC power relays,starter relays

They're local to me, but they sell a lot online. I forget the fellas name there at TX Elec, but he's very knowledgable and helpful, maybe his name is Steve?

If not this time, maybe next?

hdmoxness · 02-10-2012, 01:59 AM

Looks like an impressive source indeed! Thanks.

hdmoxness · 02-10-2012, 08:33 AM

Ok. Just back from NAPA, and as I already knew, technical information on these Echlin solenoids is hard to come by. At my request, the sales rep called their tech support and came back with ST80 & ST85 silver, ST95 copper. Well, I knew this was incorrect, so I asked for a number at Echlin (the solenoid maker) and I spoke to someone at the Echlin help line. He also could not come up with more info than I read online yesterday, but did call me back while I was driving home with my purchase to confirm to me that the ST95 has copper contacts, which is what I suspected, considering the prices. Unable to edit my posting above, I am fairly confident that these are the correct specs on these three units:

1. ST80 12V, 4 terminals, insulated base, flat bracket, silver contacts, continuous duty for extended engagement, 80 amps, low current coil 16-21 ohms, 7.5V pull in voltage, about $59.

2. ST85 12V, 4 terminals, insulated base, flat bracket, copper contacts, continuous duty, 80 amps, coil 16-21 ohms, 7.5V pull in voltage, about $62.

3. ST95 12V, 3 terminals, grounded base, flat bracket, copper contacts, continuous duty, 80 amps, coil 16-20 ohms, continuous duty, splash proof, about $40

All three are the same physical size and will mount right where the Trombetta 936 was. As previously mentioned, the insulated ones have 4 terminals and a ground wire will have to be added.

I came home with the ST80 and will start installation shortly.

hdmoxness · 02-10-2012, 12:25 PM

Installation of the ST80 went very smoothly and it’s all sealed up now. At the One Place panel, house voltage reads one thing and engine another. Press the Battery Boost switch on the dashboard and they read the same. Release the switch, voltages split up again. Start the engine, and both voltages match up again . . . at a nice, healthy 14+ volts!

Thanks to all who contributed to this and other threads on this subject. If I can help, let me know. This forum is a great place to be—a place where we all work together. What a concept!

bruceh · 07-30-2012, 03:49 PM

Sorry to tickle and old thread but I would like a clarification.

From your description, the ST80 sounds like the battery boost rather than the battery disconnect. Is this correct?

I am after the battery disconnect.

Thanks

hdmoxness · 08-01-2012, 05:34 AM

You are correct: the solenoid I replaced with the ST80 is the one for battery boost. It connects the house batteries to the engine (or chassis) battery when you push the Battery Boost switch on the dash (to provide supplemental battery power to the engine starter) or when the engine is running (so the engine charging system can charge both the engine battery and the house batteries while you roll down the road). I didn't have any problem with my battery disconnect, but in my coach (and many others, I think), these two solenoids are mounted side by side.

Followup: the ST80 continues to perform flawlessly while we are fulltiming and presently in Nova Scotia.

Additional factoid: I recently saw a card-mounted Camco solenoid hanging among the RV accessories at a Walmart. It looked for all the world just like the BB solenoid in question, and was priced much lower than what I paid. However, I did not have time to examine it for its purpose, specs, materials, or ratings.

KenzRV · 03-30-2015, 04:18 PM

Here we are; 2 1/2 years later ;>) Is your ST80 still performing flawlessly?
I need to replace the Battery Boost switch solenoid on my '04 Suncruiser as the "boost" is not happening even though it "clicks" when I push/hold the button. But from reading, it seems that this solenoid may also prevent the house batteries from getting an engine alternator charge?
At any rate, I REALLY appreciate all the background/advice you have provided hdmoxness, and would like to replace the existing with a 3-terminal silver contact version but must assume there is no such animal? (I'd rather not run another ground and prefer to just bolt in a better solenoid exactly as Winnebago had done).
Thanks!

John Hilley · 03-30-2015, 06:13 PM

Quote:

Originally Posted by KenzRV

Here we are; 2 1/2 years later ;>) Is your ST80 still performing flawlessly?
I need to replace the Battery Boost switch solenoid on my '04 Suncruiser as the "boost" is not happening even though it "clicks" when I push/hold the button. But from reading, it seems that this solenoid may also prevent the house batteries from getting an engine alternator charge?
At any rate, I REALLY appreciate all the background/advice you have provided hdmoxness, and would like to replace the existing with a 3-terminal silver contact version but must assume there is no such animal? (I'd rather not run another ground and prefer to just bolt in a better solenoid exactly as Winnebago had done).
Thanks!

You don't have to run another ground, just connect a wire from solenoid frame to ground terminal of a 4 terminal solenoid.

KenzRV · 03-30-2015, 08:36 PM

Thank you John! So a bigger eyelet under one of the mounting bolts, with a short wire and a smaller eyelet under the negative terminal of the solenoid will do the trick then?

hdmoxness · 03-31-2015, 06:52 AM

John's as quick as ever! And, as usual, he's right. I fully understand your desire to swap out the defective solenoid for an identical match, but the additional ground wire is simple and the silver contacts you are gaining are well worth it.

To answer your question, the ST80 in my '04 Suncruiser is still working flawlessly. It makes the connection between the house and engine batteries anytime the engine is running or anytime you press the boost switch, and it delivers the high current without a problem. You'll be proud and happy with this solution when you're done.

John Hilley · 03-31-2015, 07:42 AM

Quote:

Originally Posted by KenzRV

Thank you John! So a bigger eyelet under one of the mounting bolts, with a short wire and a smaller eyelet under the negative terminal of the solenoid will do the trick then?

Yes, just crimp on the appropriate ring or spade terminal on each end of a short jumper wire.

KenzRV · 03-31-2015, 12:26 PM

Thanks again John AND Dean! Online looks like my local NAPA has an ECH ST80 for $47.49, plan to pick that up tomorrow. I think it's also time for a engine battery, Costco carries Interstate (which I've had good luck with) so I think I'll pick up an 800 CCA from them for $83 plus core tomorrow as well and do it all together.
LOVE this forum! Thanks again.

KenzRV · 04-01-2015, 05:39 PM

Slam dunk!
Thanks to this forum and members Dean and John, I got it all handled today without issue! Purchased and installed my ST80 along with a new Interstate battery. Checked voltage of the house and engine batteries at the "One Place" panel and found them to be roughly 1v different, started the engine, checked again, and they were both the same (14.5v). Shut the engine off, checked and they were (again) different, had a friend hold the "Battery Boost" switch and they were both the same voltage again. ;>)
I keep the coach plugged in to a 30amp circuit at home so it's hard to say just how long my engine alternator has NOT been charging the "house" batteries? But I'm a happy camper now!
Ken

Chalet2009 · 06-19-2015, 06:39 AM

I have Winnebago Chalet 2009 (Access(200) 231J )
I replaced my original Trombbetta relay 936-1215-011-21 with Echlin ST95, per recommendations on the forum. Did NOT fix the problem.
When I Start the engine, relay never closed...
I tried it with different level of charge on house batteries: at 12V or 11.8V or 11.5V or even 11 V. However, When I press the Battery Boost switch on the dashboard everything works fine since house battery get 13.5 V from alternator. Release the switch, voltages goes down.
There is a chance I purchased a bad relay from NAPA, but before replacing it can someone explain me the logic in this type of relay. Is it working on differential? Basically if delta for the voltage is let's assume 0.2 V is it suppose to close?

Thanks

John Hilley · 06-19-2015, 08:01 AM

If it works in Boost Mode the solenoid is fine. The problem is from ignition switch to solenoid, probably a chassis fuse. What chassis do you have?

hdmoxness · 06-19-2015, 08:28 AM

This solenoid is supposed to close the contacts between the two big terminals on the left and right whenever 12V is applied to the third terminal in the middle. It does not operate off of any "differential" voltages. That middle terminal should receive 12V (1) anytime your ignition is turned ON, or (2) anytime you press the boost switch. As John says, if it works when the boost switch is pressed, but not when you turn the ignition key to ON, you have a wiring problem where the ignition-on 12V supply in your RV is not getting to the middle terminal. Indeed, it may be a fuse thing.

twinboat · 06-19-2015, 09:22 AM

Does the solenoid you changed, close, when you hit boost?

Many solinoids are controlled by a small voltage sensing circuit board, calls a BIRD.
"BI-directional Relay with Delay". It sensing charging voltage from either, alternator or charger, and sends 12 to the small post of the solenoid.

The boost switch,overrides it, or there is a second solenoid.

My older MH has 2 solinoids, 1 closes by ignition key and the other by boost switch. If they shared 1 solenoid, the boost switch would back feed the ignition circuit.

grtharris · 06-19-2015, 10:20 AM

Chalet2009, Wire KE (RUN ONLY POWER SOURCE) from Ford and wire LS (COACH FEED) connect to the boost switch. KE on the normally closed contacts and LS on the normally open contacts and wire LR on the common going to the solenoid. From what you said everything is good from the switch to the relay. Could be a bad switch or bat fuse on the Ford side. Drawings do not show which Ford fuse KE is connected to just wht/pur wire.

Chalet2009 · 06-19-2015, 10:21 AM

I attached wiring diagram.
I have Ford E 450 chassis.
I think I got the idea now.
On diagram(attached) (page 2) control signal(LR wire) comes to the middle terminal, that can be boost switch (and it works) or signal/indicator that ignition is on(page 5) coming from "Ford Run only circuit (KE wire) - sounds like this is my problem. I'm going to spend more time checking this circuit now and will let you know.
Thank you so much for details!!!